Honestly in that price range, just go to a couple of local bike shops and see what they have to offer. Any of the major brands Like Trek, Specialized,Giant etc will have almost identical offerings. I would look to see if there are any sales on last years models as well. Try a couple out too, see how they fit and feel.
After looking maybe post a couple models you are looking at and I can offer some suggestions. Or just text me from the shop..
Fairdale has a couple of "Commuter" type bikes that are nice too. Emma has one and it is a good bike for it intended use.